Figure 6. The hip trajectory and the mean and standard deviation of the kinematic and dynamic variables obtained for the default leg model.

Kinematic and dynamic variables obtained for the system with a) an appropriate set of gains, and b) an inappropriate set of gains. S refers to the stance phase (when the end effector is in touch with the ground) and F refers to the flight phase (when the end effector is in the air). In b, because each hop has a different duration, the data relative to each hop has been linearly interpolated to match the durations across different hops. Note that in this plot the time indicated for the stance-to-flight transition is only relative to the first hop. In subsequent hops, and because they progressively decrease in duration, this transition occurs earlier than illustrated by the marker. The hip trajectory recorded for the system with c) an appropriate set of gains, and d) an inappropriate set of gains.